When scientists launched the Human Genome Project back in 1990, they hoped, among other things, to crack the mystery behind the genetic origins of disease.
And, they succeeded… sort of.
As it turns out, the more we learn about how genes influence our health, the less we really know. And for all the testing and risk assessment that practically defines modern medicine, we still can’t say for certain who will get sick and who won’t.
That’s because heredity rarely carves a straight path to any disease—or necessarily any path at all. And now, as it turns out, family history is just one piece of the puzzle.
It’s a Family Affair
Let’s start with what we do know. Genes play a role in nine of the 10 leading causes of death in this country—chief among them being cancer and heart disease.1
Sometimes, this role is major. The BRCA1 and BRCA2 mutations are perfect examples of how genes can have a direct link to disease. Roughly 60 percent of women with these variations will go on to develop breast cancer.2 And this is one clear case in which genomics have enabled earlier and more effective intervention.
It’s also very rare. In general, heredity only accounts for a small piece of the pie where disease risk is concerned. In fact, estimates suggest that only five to 10 percent of cancer cases are purely hereditary.3
In conditions like heart disease and diabetes, the genetic waters can be even muddier, as environmental factors take on a larger role. Obviously, your family history provides important clues for your doctor to work from, but the bigger picture is much more complicated than a single risk factor.
Ultimately, there are non-smokers who still die from lung cancer. There are healthy weight people who still suffer from heart attacks. And, on the other side of the coin, we’ve probably all met at least one person who, despite one or several horrible health habits, continues to beat the odds.
But these are the exceptions to the rule. Time and again, research proves that environment does matter. In fact, it matters a lot.
The Real Driving Force Behind Disease
Your individual gene sequence may not be as important as the way those genes are expressed. And this comes down to epigenetic markers. These are modifications that turn your genes “on” or “off,” steering the course of your health in the process.
The catch here is that epigenetics aren’t predetermined. On the contrary, these gene changes are very much dependent upon your environment.
Take DNA methylation, for example. This process is one of the many ways that your body controls gene expression. It adds molecules to DNA in such a way as to affect its function. Errors in DNA methylation can shut down protective genes. And this, in turn, can pave the way to diseases like cancer.
But these errors don’t just happen on their own—and the trends can be reversed. Science is now turning to processes like DNA methylation as a possible focus for disease intervention. Testing early for abnormalities and blocking dangerous epigenetic changes with drug therapy is just one new route of treatment that researchers are investigating.4
It’s hardly the only way to override your genetic blueprint, however. Research shows that any number of factors—like diet, toxin exposure and activity level—can all contribute to the manner in which your DNA shapes your health.
The bottom line: So-called “bad” genes require expression to do their dirty work. They can be silenced, too. And the same rules apply to protective genes, for better or worse.
Genetic tendency in no way guarantees disease or health—especially where common conditions like cancer, heart disease and diabetes are concerned. The fact is you can prevent these diseases just as easily as you can cause them.
Changes That Last a Lifetime… and Longer
Clearly, a healthy diet is one of the golden rules of disease prevention. Everyone knows they should be eating well. But few people realize the serious epigenetic impact that your nutrition can have on your DNA—and even your offspring’s DNA.
That’s right. Your diet can affect your children’s DNA. And your grandchildren’s, too. Recent research shows that epigenetic changes aren’t erased with every new generation. And both parents’ diets can have a lasting impact on the cancer, diabetes and obesity risks of their progeny.5
The true reach of these epigenetic discoveries is only just coming to light. But it’s clear that diet is one of the strongest influences on your future health. And thanks to this emerging field of “nutrigenomics,” scientists may soon be able to develop personalized diet plans based on individual genetic risk factors.
In the meantime, we have to make smart choices based on the wealth of information that’s already out there. Assuming you are genetically predisposed to obesity, diabetes, heart disease or cancer—what then?
Well, for starters, here’s one thing you shouldn’t be eating—sugar. As dietary threats go, the latest research points to our nation’s sugar addiction as the most dangerous. A seemingly endless list of diseases traces right back to those white, processed foods, with the biggest offender being soda.
According to research published in the New England Journal of Medicine, sugary beverages directly interact with obesity-related genes.6 This suggests that sugar is much more than just empty calories. In fact, it seems to play a clear role in fast-tracking genetic tendencies toward obesity—along with the cancer, heart disease and diabetes risk that comes with it.
Now for the good news. Research also shows that a number of nutritional factors have the opposite effect—triggering epigenetic changes for the better.
For example, research has shown that resveratrol—found in grapes and red wine—can turn on longevity genes that mimic exercise, maintain weight and help to preserve youth.7 Likewise, folate—from leafy greens and cruciferous veggies like broccoli—can regulate the epigenetic DNA methylation processes that would normally lead to cancer.8
Fruits and vegetables can also influence heart disease genes. In fact, one recent study showed that it is possible to wipe out the risk associated with the 9p21 gene—one of the strongest predictors of cardiovascular disease—completely.9
How? Simply fill up on fresh produce every single day.
And that’s only accounting for epigenetic means of disease prevention. Ultimately, eating the way you know you should—a diet rich in whole, unprocessed foods and packed with plenty of fresh fruits and veggies—will slash your odds of any life-altering diagnosis in a number of ways.
Research continues to support the power of everyday food choices—things like cold-water fish, fiber, green tea, fruits, veggies, herbs and spices—to fight oxidative stress, soothe inflammation and nourish essential biological processes.
The end result is lower risk of cancer, heart disease, diabetes, Alzheimer’s and more. Simply put, smart nutrition keeps you alive. In fact, studies show that even something as simple as adding a multivitamin to your daily regimen could mean the difference between disease and health.10-11
Outrunning Your Genetic Hand
Exercise is an equally important part of the epigenetic equation. To this point, a recent study shows that exercise also influences DNA methylation, triggering critical metabolic adaptations in your muscle tissue.
These epigenetic changes enhance your body’s ability to generate fat-burning proteins. And they begin to take shape from the moment you start exercising—regardless of how sedentary you were beforehand.12
Clearly, the benefits of any workout may be more profound (not to mention longer-lasting) than once thought, especially if you’re predisposed to obesity. But more than that, regular exercise is just plain smart for your health—regardless of your genetic makeup.
One review of over 40 published papers revealed that routine workouts cut your risk of nearly two dozen different chronic conditions. (That includes cancer, heart disease, dementia, stroke, type 2 diabetes, depression, obesity and high blood pressure, just to list a few.)13
Meanwhile, prolonged sitting—whether in front of the TV or at a desk job—raises your risk of dying from any cause by as much as 37 percent.14
It’s not hard to connect the dots. If you want to stay healthy, you have to keep moving.
Live Clean, Live Connected
Diet and exercise may be the two main factors that can help you level the genetic playing field. But you shouldn’t underestimate the insidious role that environmental toxins play in disease formation either.
Not smoking is an obvious way to cut your risk of heart attack, stroke, cancer—you name it. Nevertheless, the toxins you can’t see—but still encounter daily—could wind up causing just as much trouble. These include things like BPA, PCBs, parabens and other similar disease-promoting toxins.
Unfortunately, it is practically impossible to avoid all of these chemicals in the modern world. But you can limit your exposure, learning what they are and where they exist so you can try to work systematically to remove certain products from your life.
The Environmental Working Group (EWG) offers an extensive, searchable database that details the toxin profiles of the most popular household and hygiene products. They’re also the consumer watchdog behind those annual “Dirty Dozen” and “Clean Fifteen” lists.
Resources like this—detailing which produce is safe to buy conventional, and which should always be organic—make taking on toxins a whole lot easier.
Of course, then there are the little things that can maximize health with age—factors like better sleep. Studies indicate that getting at least seven hours of sleep every night can significantly cut your risk of multiple diseases, including diabetes, heart disease, obesity and depression.15
Even something as simple as staying socially connected and mentally engaged can make a huge difference. Research shows that while genes do matter, older adults who continue to put their brains to work for them enjoy sharper memories past retirement than their less engaged peers.16
This, of course, suggests that age-related brain drain isn’t so inevitable, after all. And it also illustrates that, despite all the genomic breakthroughs of the 21st century, the real secret to staying healthy is anything but high-tech—or even genetic as it turns out.
- CDC Fact Sheet. “Genomics and Health” http://www.cdc.gov/genomics/public/index.htm.
- National Cancer Institute Face Sheet. “BRCA1 and BRCA2: Cancer Risk and Genetic Testing.” http://www.cancer.gov/cancertopics/factsheet/risk/brca.
- Anand, P. Pharm Res. 2008 September; 25(9): 2097–116.
- McCredie, Jane. “How epigenetics is changing our fight with disease.” http://www.abc.net.au/science/articles/2009/10/01/2702198.htm.
- Cloud, John. “Why your DNA isn’t your destiny.” Time 06 Jan 2010.
- Qi Q, et al. N Engl J Med. 2012 Oct 11;367(15):1387-96.
- Healy, Melissa. “Resveratrol’s anti-aging potential gets a boost in study.” Los Angeles Times 01 May 2012.
- Higdon, Jane. “Cruciferous vegetables and cancer risk.” http://lpi.oregonstate.edu/ss06/vegetables.html.
- Carollo, Kim. “Fruits and vegetables could modify gene linked to heart disease.” http://abcnews.go.com/Health/fruits-vegetables-change-gene-linked-heart-disease/story?id=14713782#.ULeWrddcSM0.
- Gaziano J, et al. JAMA. 2012;308(18):1871-1880.
- Ames BN, et al. Nat Rev Cancer. 2002 Sep;2(9):694-704.
- Barrès R, et al. Cell Metab. 2012 Mar 7;15(3):405-11.
- Wiley – Blackwell. “Regular exercise reduces large number of health risks including dementia and some cancers, study finds.” ScienceDaily, 16 Nov. 2010.
- “How to cut your death risk: Just get off your duff.” LiveScience. 23 July 2012.
- CDC Fact Sheet. “Sleep and chronic disease.” http://www.cdc.gov/sleep/about_sleep/chronic_disease.htm.
- Umeå universitet. “Maintain your brain: The secrets to aging success.” ScienceDaily, 27 Apr. 2012.